Just a couple of weeks ago, I read that there were gene edited twins born in China.
Apparently gene editing technology was used to give these babies HIV resistance.
There were two responses: one was a message of hope about eradicating disease, the other
was horror that gene editing was used without knowing fully what the risks are.
Personally I just felt confused.
Among all of this noise I found it so difficult to put my finger on exactly what’s going
on.
So I decided to put my thinking cap on, to have a closer look at the world of gene editing
and CRISPR.
The first question is, what is CRISPR?
Here’s my basic version.
If you’re looking for a more technical explanation I’ll leave some links in the description.
Basically, CRISPR Cas9 is a gene editing tool.
It’s like having a pair of highly programmable scissors that can cut DNA at a specific point.
Once the DNA is cut, you can then either leave it or add genetic material back in.
The name of the scissors is Cas9 – a enzyme that can bind to DNA and snip it depending
on the instructions that you provide.
For example, in the case of the CRISPR babies, Dr He took sperm from a HIV positive father
and an egg from a HIV negative mother.
During IVF, he added in this Cas9 enzyme that was programmed to disable a gene called CCR5.
It is known that HIV uses this CCR5 protein as a backdoor into infect immune cells.
So Dr He hypothesized that if this CCR5 gene can be disabled, then this will lead to resistance
against HIV.
This sounds promising apart from the fact that we don’t really know what happens when
you disable this gene in a real human.
The hard part about human biology is that everything is so interconnected in very complex
ways.
Even if this specific gene edit was successful, we don’t know what kind of unintended consequences
there may be, for example, poor functioning of the immune system.
Now let’s step away from Dr He’s experiment and talk about CRISPR as a whole.
The key differences between CRISPR and other gene editing techniques, is that CRISPR is
very precise and relatively inexpensive.
It is thought that one day, maybe CRISPR will eliminate genetic diseases, and maybe we can
genetically engineer people to be stronger, smarter and more resistant to conditions like
cancer.
On the flip side there is fear that this would bring eugenics back from the dead.
In a race of super humans, what would happen to the weak and feeble?
My personal prediction is that the reality is likely to be a bit different from either
of these visions.
I see CRISPR as a new technology, and history has some important lessons about the life
cycle of new tech like CRISPR.
Let’s borrow a concept from the world of tech called the Gartner Hype Cycle.
Initially when there is a technology breakthrough, there is a lot of hope about potential benefits.
Just think about Bitcoin, after its initial development, there was this huge hype train
about how Bitcoin was going to replace everything and currency would become obsolete.
At this point, the benefits are usually overstated and the obstacles are not considered.
After this initial peak of enthusiasm, we started to learn that bitcoin had its own
disadvantages.
Meanwhile we learned that there are some genuine uses of blockchain technology, like in logistics.
And so through a slow process of learning, we’ve learnt where block chain works well,
and so it’s being incorporated into existing systems.
My thinking is that with CRISPR, we are around this point of high expectations.
It’s definitely a technological breakthrough, but there’s a lot of things that we don’t
know.
For example, the elephant in the room is that even though we know how to edit genes, we
don’t fully understand the human genome in the first place.
Yes, we’ve mapped the human genome and we know we have around 20 000 genes.
But that part, is only 1.2 percent of the entire human genome.
The other 98.8 percent is called non coding DNA, and we don’t know a lot about what
this does.
My prediction for CRISPR is that we will move from the point of high expectations, to a
point when we realise that are some real obstacles to its use.
And slowly we will learn where CRISPR works best, and where it doesn’t.
In the long term, I can definitely see gene editing being used for a certain set of diseases.
First we might treat diseases with single gene mutations like Sickle Cell Anemia, and
then move onto more complex ones.
As for creating super humans, we need to know a lot more about our DNA before we can get
close to that one, not to mention all the ethical issues.
So at the end of the day, I’m still excited for a future where more diseases are treatable
or eradicated completely.
The thing is progress in medicine is slow because its not just about having new technology,
its also about using it responsibly and ethically.
Over the coming years, I think we should expect to hear more stories about CRISPR, and when
we do have another significant breakthrough, I’ll be back with my thinking cap to break
it down for you.
Thanks for watching and I’ll see you in the next one.